PW(8) BSD System Manager's Manual PW(8)
pw -- create, remove, modify & display system users and groups
pw [-V etcdir] useradd [name|uid] [-C config] [-q] [-n name] [-u uid] [-c comment] [-d dir]
[-e date] [-p date] [-g group] [-G grouplist] [-m] [-M mode] [-k dir] [-w method]
[-s shell] [-o] [-L class] [-h fd | -H fd] [-N] [-P] [-Y]
pw [-V etcdir] useradd [name|uid] -D [-C config] [-q] [-b dir] [-e days] [-p days]
[-g group] [-G grouplist] [-k dir] [-M mode] [-u min,max] [-i min,max] [-w method]
[-s shell] [-y path]
pw [-V etcdir] userdel [name|uid] [-n name] [-u uid] [-r] [-Y]
pw [-V etcdir] usermod [name|uid] [-C config] [-q] [-n name] [-u uid] [-c comment] [-d dir]
[-e date] [-p date] [-g group] [-G grouplist] [-l name] [-m] [-M mode] [-k dir]
[-w method] [-s shell] [-L class] [-h fd | -H fd] [-N] [-P] [-Y]
pw [-V etcdir] usershow [name|uid] [-n name] [-u uid] [-F] [-P] [-7] [-a]
pw [-V etcdir] usernext [-C config] [-q]
pw [-V etcdir] groupadd [group|gid] [-C config] [-q] [-n group] [-g gid] [-M members] [-o]
[-h fd | -H fd] [-N] [-P] [-Y]
pw [-V etcdir] groupdel [group|gid] [-n name] [-g gid] [-Y]
pw [-V etcdir] groupmod [group|gid] [-C config] [-q] [-n name] [-g gid] [-l name]
[-M members] [-m newmembers] [-d oldmembers] [-h fd | -H fd] [-N] [-P] [-Y]
pw [-V etcdir] groupshow [group|gid] [-n name] [-g gid] [-F] [-P] [-a]
pw [-V etcdir] groupnext [-C config] [-q]
pw [-V etcdir] lock [name|uid] [-C config] [-q]
pw [-V etcdir] unlock [name|uid] [-C config] [-q]
The pw utility is a command-line based editor for the system user and group files, allowing
the superuser an easy to use and standardized way of adding, modifying and removing users
and groups. Note that pw only operates on the local user and group files. NIS users and
groups must be maintained on the NIS server. The pw utility handles updating the passwd,
master.passwd, group and the secure and insecure password database files, and must be run as
The first one or two keywords provided to pw on the command line provide the context for the
remainder of the arguments. The keywords user and group may be combined with add, del, mod,
show, or next in any order. (For example, showuser, usershow, show user, and user show all
mean the same thing.) This flexibility is useful for interactive scripts calling pw for
user and group database manipulation. Following these keywords, you may optionally specify
the user or group name or numeric id as an alternative to using the -n name, -u uid, -g gid
The following flags are common to most or all modes of operation:
-V etcdir This flag sets an alternate location for the password, group and configuration
files, and may be used to maintain a user/group database in an alternate loca-
tion. If this switch is specified, the system /etc/pw.conf will not be
sourced for default configuration data, but the file pw.conf in the specified
directory will be used instead (or none, if it does not exist). The -C flag
may be used to override this behaviour. As an exception to the general rule
where options must follow the operation type, the -V flag may be used on the
command line before the operation keyword.
-C config By default, pw reads the file /etc/pw.conf to obtain policy information on how
new user accounts and groups are to be created. The -C option specifies a
different configuration file. While most of the contents of the configuration
file may be overridden via command-line options, it may be more convenient to
keep standard information in a configuration file.
-q Use of this option causes pw to suppress error messages, which may be useful
in interactive environments where it is preferable to interpret status codes
returned by pw rather than messing up a carefully formatted display.
-N This option is available in add and modify operations, and tells pw to output
the result of the operation without updating the user or group databases. You
may use the -P option to switch between standard passwd and readable formats.
-Y Using this option with any of the update modes causes pw to run make(1) after
changing to the directory /var/yp. This is intended to allow automatic updat-
ing of NIS database files. If separate passwd and group files are being used
by NIS, then use the -y path option to specify the location of the NIS passwd
database so that pw will concurrently update it with the system password data-
The following options apply to the useradd and usermod commands:
-n name Specify the user/account name.
-u uid Specify the user/account numeric id.
Usually, you only need to provide one or the other of these options, as the
account name will imply the uid, or vice versa. However, there are times when
you need to provide both. For example, when changing the uid of an existing
user with usermod, or overriding the default uid when creating a new account.
If you wish pw to automatically allocate the uid to a new user with useradd,
then you should not use the -u option. You may also provide either the
account or userid immediately after the useradd, userdel, usermod or usershow
keywords on the command line without using the -n or -u options.
-c comment This field sets the contents of the passwd GECOS field, which normally con-
tains up to four comma-separated fields containing the user's full name,
office or location, and work and home phone numbers. These sub-fields are
used by convention only, however, and are optional. If this field is to con-
tain spaces, you need to quote the comment itself with double quotes '"'.
Avoid using commas in this field as these are used as sub-field separators,
and the colon ':' character also cannot be used as this is the field separator
for the passwd file itself.
-d dir This option sets the account's home directory. Normally, you will only use
this if the home directory is to be different from the default determined from
/etc/pw.conf - normally /home with the account name as a subdirectory.
-e date Set the account's expiration date. Format of the date is either a UNIX time
in decimal, or a date in 'dd-mmm-yy[yy]' format, where dd is the day, mmm is
the month, either in numeric or alphabetic format ('Jan', 'Feb', etc) and year
is either a two or four digit year. This option also accepts a relative date
in the form '+n[mhdwoy]' where 'n' is a decimal, octal (leading 0) or hexadec-
imal (leading 0x) digit followed by the number of Minutes, Hours, Days, Weeks,
Months or Years from the current date at which the expiration date is to be
-p date Set the account's password expiration date. This field is similar to the
account expiration date option, except that it applies to forced password
changes. This is set in the same manner as the -e option.
-g group Set the account's primary group to the given group. group may be defined by
either its name or group number.
-G grouplist Set additional group memberships for an account. grouplist is a comma, space
or tab-separated list of group names or group numbers. The user's name is
added to the group lists in /etc/group, and removed from any groups not speci-
fied in grouplist. Note: a user should not be added to their primary group
with grouplist. Also, group membership changes do not take effect for current
user login sessions, requiring the user to reconnect to be affected by the
-L class This option sets the login class for the user being created. See
login.conf(5) and passwd(5) for more information on user login classes.
-m This option instructs pw to attempt to create the user's home directory.
While primarily useful when adding a new account with useradd, this may also
be of use when moving an existing user's home directory elsewhere on the file
system. The new home directory is populated with the contents of the skeleton
directory, which typically contains a set of shell configuration files that
the user may personalize to taste. Files in this directory are usually named
dot.<config> where the dot prefix will be stripped. When -m is used on an
account with usermod, existing configuration files in the user's home direc-
tory are not overwritten from the skeleton files.
When a user's home directory is created, it will by default be a subdirectory
of the basehome directory as specified by the -b option (see below), bearing
the name of the new account. This can be overridden by the -d option on the
command line, if desired.
-M mode Create the user's home directory with the specified mode, modified by the cur-
rent umask(2). If omitted, it is derived from the parent process' umask(2).
This option is only useful in combination with the -m flag.
-k dir Set the skeleton directory, from which basic startup and configuration files
are copied when the user's home directory is created. This option only has
meaning when used with the -d or -m flags.
-s shell Set or changes the user's login shell to shell. If the path to the shell pro-
gram is omitted, pw searches the shellpath specified in /etc/pw.conf and fills
it in as appropriate. Note that unless you have a specific reason to do so,
you should avoid specifying the path - this will allow pw to validate that the
program exists and is executable. Specifying a full path (or supplying a
blank "" shell) avoids this check and allows for such entries as /nonexistent
that should be set for accounts not intended for interactive login.
-h fd This option provides a special interface by which interactive scripts can set
an account password using pw. Because the command line and environment are
fundamentally insecure mechanisms by which programs can accept information, pw
will only allow setting of account and group passwords via a file descriptor
(usually a pipe between an interactive script and the program). sh, bash, ksh
and perl all possess mechanisms by which this can be done. Alternatively, pw
will prompt for the user's password if -h 0 is given, nominating stdin as the
file descriptor on which to read the password. Note that this password will
be read only once and is intended for use by a script rather than for interac-
tive use. If you wish to have new password confirmation along the lines of
passwd(1), this must be implemented as part of an interactive script that
If a value of '-' is given as the argument fd, then the password will be set
to '*', rendering the account inaccessible via password-based login.
-H fd Read an encrypted password string from the specified file descriptor. This is
like -h, but the password should be supplied already encrypted in a form suit-
able for writing directly to the password database.
It is possible to use useradd to create a new account that duplicates an existing user id.
While this is normally considered an error and will be rejected, the -o option overrides the
check for duplicates and allows the duplication of the user id. This may be useful if you
allow the same user to login under different contexts (different group allocations, differ-
ent home directory, different shell) while providing basically the same permissions for
access to the user's files in each account.
The useradd command also has the ability to set new user and group defaults by using the -D
option. Instead of adding a new user, pw writes a new set of defaults to its configuration
file, /etc/pw.conf. When using the -D option, you must not use either -n name or -u uid or
an error will result. Use of -D changes the meaning of several command line switches in the
useradd command. These are:
-D Set default values in /etc/pw.conf configuration file, or a different named
configuration file if the -C config option is used.
-b dir Set the root directory in which user home directories are created. The
default value for this is /home, but it may be set elsewhere as desired.
-e days Set the default account expiration period in days. Unlike use without -D, the
argument must be numeric, which specifies the number of days after creation
when the account is to expire. A value of 0 suppresses automatic calculation
of the expiry date.
-p days Set the default password expiration period in days.
-g group Set the default group for new users. If a blank group is specified using -g
"", then new users will be allocated their own private primary group with the
same name as their login name. If a group is supplied, either its name or uid
may be given as an argument.
-G grouplist Set the default groups in which new users are granted membership. This is a
separate set of groups from the primary group, and you should avoid nominating
the same group as both primary and extra groups. In other words, these extra
groups determine membership in groups other than the primary group. grouplist
is a comma-separated list of group names or ids, and are always stored in
/etc/pw.conf by their symbolic names.
-L class This option sets the default login class for new users.
-k dir Set the default skeleton directory, from which prototype shell and other ini-
tialization files are copied when pw creates a user's home directory. See
description of -k for naming conventions of these files.
-u min,max, -i min,max
These options set the minimum and maximum user and group ids allocated for new
accounts and groups created by pw. The default values for each is 1000 mini-
mum and 32000 maximum. min and max are both numbers, where max must be
greater than min, and both must be between 0 and 32767. In general, user and
group ids less than 100 are reserved for use by the system, and numbers
greater than 32000 may also be reserved for special purposes (used by some
-w method The -w option sets the default method used to set passwords for newly created
user accounts. method is one of:
no disable login on newly created accounts
yes force the password to be the account name
none force a blank password
random generate a random password
The 'random' or 'no' methods are the most secure; in the former case, pw gen-
erates a password and prints it to stdout, which is suitable where you issue
users with passwords to access their accounts rather than having the user nom-
inate their own (possibly poorly chosen) password. The 'no' method requires
that the superuser use passwd(1) to render the account accessible with a pass-
-y path This sets the pathname of the database used by NIS if you are not sharing the
information from /etc/master.passwd directly with NIS. You should only set
this option for NIS servers.
The userdel command has only three valid options. The -n name and -u uid options have
already been covered above. The additional option is:
-r This tells pw to remove the user's home directory and all of its contents.
The pw utility errs on the side of caution when removing files from the sys-
tem. Firstly, it will not do so if the uid of the account being removed is
also used by another account on the system, and the 'home' directory in the
password file is a valid path that commences with the character '/'. Sec-
ondly, it will only remove files and directories that are actually owned by
the user, or symbolic links owned by anyone under the user's home directory.
Finally, after deleting all contents owned by the user only empty directories
will be removed. If any additional cleanup work is required, this is left to
Mail spool files and crontabs are always removed when an account is deleted as these are
unconditionally attached to the user name. Jobs queued for processing by at are also
removed if the user's uid is unique and not also used by another account on the system.
The usermod command adds one additional option:
-l name This option allows changing of an existing account name to 'name'. The new
name must not already exist, and any attempt to duplicate an existing account
name will be rejected.
The usershow command allows viewing of an account in one of two formats. By default, the
format is identical to the format used in /etc/master.passwd with the password field
replaced with a '*'. If the -P option is used, then pw outputs the account details in a
more human readable form. If the -7 option is used, the account details are shown in v7
format. The -a option lists all users currently on file. Using -F forces pw to print the
details of an account even if it does not exist.
The command usernext returns the next available user and group ids separated by a colon.
This is normally of interest only to interactive scripts or front-ends that use pw.
The -C and -q options (explained at the start of the previous section) are available with
the group manipulation commands. Other common options to all group-related commands are:
-n name Specify the group name.
-g gid Specify the group numeric id.
As with the account name and id fields, you will usually only need to supply
one of these, as the group name implies the uid and vice versa. You will
only need to use both when setting a specific group id against a new group or
when changing the uid of an existing group.
-M memberlist This option provides an alternative way to add existing users to a new group
(in groupadd) or replace an existing membership list (in groupmod).
memberlist is a comma separated list of valid and existing user names or
-m newmembers Similar to -M, this option allows the addition of existing users to a group
without replacing the existing list of members. Login names or user ids may
be used, and duplicate users are silently eliminated.
-d oldmembers Similar to -M, this option allows the deletion of existing users from a group
without replacing the existing list of members. Login names or user ids may
be used, and duplicate users are silently eliminated.
groupadd also has a -o option that allows allocation of an existing group id to a new group.
The default action is to reject an attempt to add a group, and this option overrides the
check for duplicate group ids. There is rarely any need to duplicate a group id.
The groupmod command adds one additional option:
-l name This option allows changing of an existing group name to 'name'. The new
name must not already exist, and any attempt to duplicate an existing group
name will be rejected.
Options for groupshow are the same as for usershow, with the -g gid replacing -u uid to
specify the group id. The -7 option does not apply to the groupshow command.
The command groupnext returns the next available group id on standard output.
The pw utility supports a simple password locking mechanism for users; it works by prepend-
ing the string '*LOCKED*' to the beginning of the password field in master.passwd to prevent
The lock and unlock commands take a user name or uid of the account to lock or unlock,
respectively. The -V, -C, and -q options as described above are accepted by these commands.
For a summary of options available with each command, you can use
pw [command] help
pw useradd help
lists all available options for the useradd operation.
The pw utility allows 8-bit characters in the passwd GECOS field (user's full name, office,
work and home phone number subfields), but disallows them in user login and group names.
Use 8-bit characters with caution, as connection to the Internet will require that your mail
transport program supports 8BITMIME, and will convert headers containing 8-bit characters to
7-bit quoted-printable format. sendmail(8) does support this. Use of 8-bit characters in
the GECOS field should be used in conjunction with the user's default locale and character
set and should not be implemented without their use. Using 8-bit characters may also affect
other programs that transmit the contents of the GECOS field over the Internet, such as
fingerd(8), and a small number of TCP/IP clients, such as IRC, where full names specified in
the passwd file may be used by default.
The pw utility writes a log to the /var/log/userlog file when actions such as user or group
additions or deletions occur. The location of this logfile can be changed in pw.conf(5).
/etc/master.passwd The user database
/etc/passwd A Version 7 format password file
/etc/login.conf The user capabilities database
/etc/group The group database
/etc/pw.conf Pw default options file
/var/log/userlog User/group modification logfile
The pw utility returns EXIT_SUCCESS on successful operation, otherwise pw returns one of the
following exit codes defined by sysexits(3) as follows:
o Command line syntax errors (invalid keyword, unknown option).
o Attempting to run one of the update modes as non-root.
o Memory allocation error.
o Read error from password file descriptor.
o Bad or invalid data provided or missing on the command line or via the password
o Attempted to remove, rename root account or change its uid.
o Skeleton directory is invalid or does not exist.
o Base home directory is invalid or does not exist.
o Invalid or non-existent shell specified.
o User, user id, group or group id specified does not exist.
o User or group recorded, added, or modified unexpectedly disappeared.
o No more group or user ids available within specified range.
o Unable to rewrite configuration file.
o Error updating group or user database files.
o Update error for passwd or group database files.
o No base home directory configured.
chpass(1), passwd(1), umask(2), group(5), login.conf(5), passwd(5), pw.conf(5), pwd_mkdb(8),
The pw utility was written to mimic many of the options used in the SYSV shadow support
suite, but is modified for passwd and group fields specific to the 4.4BSD operating system,
and combines all of the major elements into a single command.
BSD October 29, 2012 BSD